Japanese Patent Application Laid-Open No. 2000-154674 discloses a conventional electric steering locking apparatus of this kind. This electric steering locking apparatus mainly includes a cam member that rotates in an unlocking direction and a locking direction by driving operation of a drive source, a locking member that follows a sliding surface of the cam member and moves between a locking position where the rotation of a steering shaft is locked and an unlocking position where the rotation of the steering shaft is permitted, a spring that biases the locking member toward the locking position, and a steering lock preventing unit that holds the locking member in the unlocking position.
The steering lock preventing unit includes a holding lever connected to an operation knob through a connection member. When the holding lever enters an engaging groove of the locking member located in the unlocking position, the locking member is locked.
With the above configuration, while a vehicle is parked, the locking member is located in the locking position and the steering shaft is locked. Thus, the vehicle can be theftproof during parking.
When a parked vehicle is to be driven, the cam member rotates in the unlocking direction by the driving operation of the drive source, the locking member is brought into the unlocking position, and the rotation of the steering shaft is permitted. When the locking member is located in the unlocking position, the holding lever of the steering lock preventing unit enters into the engaging groove of the locking member, and the locking member is locked so as not to move to the locking position. With this configuration, even when an external force toward the locking position is applied to the cam member or the locking member due to abrupt vibration or the like during running, it is possible to prevent the locking member biased by the spring from moving toward the locking position to lock the steering shaft.